title: Effects of dexmedetomidine on cerebral blood flow in critically ill patients with or without traumatic brain injury: a prospective controlled trial.
abstract: OBJECTIVE
  To examine the effect of dexmedetomidine on CBF in critical ill patients with or without TBI.
  
  
  METHODS
  Prospective controlled trial (ISRCTN57998533).
  
  
  METHODS
  Fifteen patients without TBI and 20 patients with TBI with a Glasgow Coma Scale score of 4-14 were assigned to CON or TBI groups, respectively. All patients received 1 μg kg(-1) dexmedetomidine infused over 10 minutes, followed by a 0.4 μg kg(-1)h(-1) continuous infusion for 60 minutes. Blood pressure was maintained at the pre-sedation level with dopamine for all patients. The CBF and cerebral metabolic rate equivalent (CMRe) were measured before sedation and 70 minutes after dexmedetomidine administration.
  
  
  RESULTS
  Dexmedetomidine administration significantly decreased CBF in patients of the CON group (difference = 3.3 ml s(-1), 95% confidence interval [CI] = 0.92-5.7 ml s(-1), p = 0.008), without altering the CMRe and CMRe/CBF ratio. The dexmedetomidine-induced change of CBF, CMRe and CMRe/CBF was not significant in the TBI group. The percentage of CBF reduction was greater in the CON group than in the TBI group (difference = 13.9%, 95% CI = 5.5-22.2%, p = 0.002).
  
  
  CONCLUSIONS
  Dexmedetomidine may be used in patients with TBI without risk of affecting brain oxygenation.
authors.affiliation: Intensive Care Unit, Shanghai Sixth People's Hospital, Medical College of Shanghai Jiaotong University , Shanghai , PR China .
authors.forename: Xuemin
authors.initials: X
authors.lastname: Wang
authors.forename: Junhui
authors.initials: J
authors.lastname: Ji
authors.forename: Liang
authors.initials: L
authors.lastname: Fen
authors.forename: Aizhong
authors.initials: A
authors.lastname: Wang
mesh_terms: D000328:Adult; D001794:Blood Pressure / Q000187:drug effects*; D001930:Brain Injuries / Q000188:drug therapy / Q000503:physiopathology*; D002560:Cerebrovascular Circulation / Q000187:drug effects*; D016638:Critical Illness; D020927:Dexmedetomidine / Q000008:administration & dosage* / Q000494:pharmacology; D005260:Female; D015600:Glasgow Coma Scale; D006339:Heart Rate / Q000187:drug effects*; D006801:Humans; D006993:Hypnotics and Sedatives / Q000008:administration & dosage* / Q000494:pharmacology; D007427:Intracranial Pressure; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D016896:Treatment Outcome
chemical_list: D006993:Hypnotics and Sedatives; D020927:Dexmedetomidine